Question about carts
 

So to start things off, let me explain, for a little off season project, i thought that having a multi-purpose workbench/tool-chest/battery station is much more practical then chargers on the floor, using the totes as tool chests, and other problems that were had in my teams rookie year, (2013 was 4519's first season).

From all that i was wondering if there are regulations in place against having say a deep cycle battery on the cart that can provide power to power bars, battery chargers, and so on.

I was thinking that the cart would be designed to fit in a 36" doorway, and to be a couple feet long, 3'-6' perhaps. my design for the cart would all start with a main power in, a power cord, running from the main cart battery to an outlet for recharges. at that point there would be the battery, for that i would plan to have a master switch that when flipped cuts all power on the cart, both to and from the battery (in case of sudden problems, and for overnight situations), i would plan for it to also have a little information panel easily accessible that would display the battery's current charge and such.
From there the battery would just run to appropriate transformers to make the power safe for being hooked up to power bars, the classmate DS, and battery chargers

Apart from all electrical, it would just have some drawers of a cupboard with all the super important tools that would need easy access.
back to the original question, Is there anything governing the use of large battery's on carts?

also if anyone has any ideas or tips for improvement of the cart design, please leave a comment, Thanks!

Have a great day everyone!

-Connor

Re: Question about carts
 

I can't think of any rule about having a deep cycle battery on a cart per se. However, the one caveat on that is that safety is going to be probably your #1 driving requirement, even above having all the appropriate space. (Not that space will be an issue, necessarily.) The main breaker that cuts the battery out of the system is an excellent start.

Now, the question then becomes: Where do you plan to use this cart, primarily? Obviously, in the pit, which has a power drop (thereby making the large battery unnecessary); where else do you anticipate using the cart (and what are the odds of a power outlet being nearby)?

Re: Question about carts
 

20 has a robot cart that helps to carry a toolchest, batteries, and other necessary tools. And while it seems nice and convenient (and it sometimes is), it's very heavy and difficult to push around to matches.

Now even if it were to be just a setup for your pits, you have to figure out how to transport the cart to the venue. Our cart is somewhat tall, so the shelving and handle detach for transporting it to events.

I would recommend a separate lightweight, maneuverable cart, a separate tool chest, separate battery charging stations (easy enough to make out of wood), and a separate driver's station. You could set up the drivers station charger in your pits. You could also attach a robot battery and inverter to your drivers station in order to charge your laptop in a clinch.

If the totes aren't working for you as tool chests, try out different ways to store your tools. Partition your totes, use excessive labeling. If you have the funds, purchase a sliding drawer tool chest or build one.

I feel like I'm being rather unhelpful toward what you were asking, but from our team's experience, an all-in-one cart sounds good, but it can be implemented poorly very easily.

I'd love to see you have some success with this, and if you do, post pictures!

Re: Question about carts
 

Well the cart would of course be in the pit, and around my school the majority of our testing is done in our gym, which is not an idea distance to be running back and fourth for things like battery's, and also for the space we have in the school, we have to keep everything in the smallest area possible, (we have a small classroom as a workshop).

To your point on the pits having power, making the battery a little redundant, and event that happened at the regional my team attended was one of the power power lines failed because the generator died, and where our pit was there were not other close by power sources, so we were powerless for about 4 or 5 hours, so its basically a better safe then sorry feature.

If you want to have a "cart" like pit setup, I would do some research on wheels, and wheel setups. You need to have the right wheels for the amount it will carry(a lot) and it should not be able to easily drift(don't do 4 casters). One tip I would give is make sure you have breaks. So if someone worked on the workbench, it wouldn't move away into the next pit. :) Also, with any electrical work you do, make sure it is safe enough to pass safety in the pits and is weather proof.(you never know when a thunderstorm is coming) As for maneuverability, I would look into a pull cart kind of system. And if you plan on buying this cart and modifying it, most of the above is redundant. :)

Re: Question about carts
 

There are those that would tell you that 2 steering and 2 fixed is good for large-ish, heavy-ish rolling devices. Let's just say that I heartily disagree, from experience, and suggest 4 casters, all locking. You may need a second person either pulling or pushing, but it'll be a lot easier to manage in a tight space, say the pit aisles or the classroom, if you have the ability to go side to side. And if they're all locking, trying to move the cart will be made very difficult, even if you can't get to one or two to lock them.

Make sure you can go over a large cable protector in any case--figure about 2-3 inches vertical and about the same or maybe a little longer horizontal.

Re: Question about carts
 

well being able to support the weight is something im not too too worried about, because mcmaster carr has some very heavy duty wheels for a good price, (can hold a few thousand pounds)


When i do electrical, i do everything in my power to make sure, its safe, perfect, and also pretty, because ugly wiring is ugly, and the weatherproofing is also not much of an issue, but the battery will have some form of leak-proof box, for weather reasons as well as battery spills.

Re: Question about carts
 

In what situations would you need to use the battery you want in the cart? In your build space or gym, you should be able to get to an outlet, even if you need an extension cord. In the pits, power is provided for you. Personally, I don't think the possible gain from having the battery is worth the headache of safety concerns.

That said, here are a few pictures of our battery cart:
http://www.chiefdelphi.com/media/photos/35787
http://www.chiefdelphi.com/media/photos/35786
http://www.chiefdelphi.com/media/photos/35785

Features:
- Charging for both robot and drill batteries
- Main power switch that kills power to the entire cart
- Relays between the chargers and the Anderson connectors to prevent draining the batteries when the power is off (the chargers will slowly drain the batteries otherwise!)
- External power strip
- Lockable wheels to give a sturdy base (two fixed, two caster)
- Bolted down vice
- Sturdy work surface - you can really pound on something here, unlike on the tables usually included in the pits at events.
- Not only fits through standard doors, but it can be laid flat on its back to fit in the storage compartment beneath most coach buses (this was really important, until we got our trailer).
- Additional storage room, sized to fit a standard FRC tote, on end (generally PR stuff for the stands goes in here to be carried up later)
- It's heavy. Very heavy. Fully loaded, it takes 4 adults to lift it into the trailer.

Note that we have a foll-sized tool chest (on wheels) for all of our tools that gets wheeled in everywhere with us, as well as a set of cabinets (on wheels) that holds other tools and supplies (The cabinets come apart when we get to the pits and go in either corner, and include supports for our pit banners).

Re: Question about carts
 

You will want to design it for a 30" door opening. While 36" is the standard for exterior doors, many interior doors are 30" or 32". That one time you need to go through a narrow door, you'll be thankful.

I agree with the points about not having an unnecessarily complex charging system on the cart. Just get some battery chargers and extension cords. You should never be without wall power. Safety inspectors may tell you to disconnect a charging system for a deep cycle battery in the pits.

I also agree with others' statements regarding separate carts. Don't try to have a single cart for everything; instead, separate it out into mechanical, electrical, and battery charging. These don't need to be massive carts. Electrical may only need an 18"x18" table top and chest of drawers.

A good project for sure!

Re: Question about carts
 

The one thing that I would caution is having motorized wheels on the cart. If the motors or batteries die mid-competition then you will have to manually push the cart. We used to have a motorized one until we had this happen; from what I heard it was not a fun experience for the whole weekend at championships. Our current cart is really versatile (parts can be shifted quickly, it is light, and allows access to the under-side of the bot) but does not house anything besides the robot.

Re: Question about carts
 

I suppose if in doubt make the cart modular.
If you show up and get told to remove something then you can just do it.

Then if you want the battery but can't use it you can just remove it.
If you make it somehow motorized you can just undo it.

Just make sufficient cavities for the desired accessories.

Re: Question about carts
 

if you don't mind my asking, what did did you use for the top of the cart, and also the internal support?

Re: Question about carts
 

One thing i should clear up, is that this cart will mostly stay in the pit, so pushing it around is not too much of a concern.

it has been designed to fit through through a 30" doorway, if i remember correctly the design is 28" wide.

after some thinking about what everyone has been saying about the battery not really being needed, I have decided to remove it from the design.

i should clear up that this would basically be my teams tool chest as we currently do not have one. Also there would be a different cart for the robot transportation. (basically some plywood with support on wheels.

Re: Question about carts
 

Deep cycle batteries are not allowed in the event. Some regionals don't care but the one I was a safety advisor at, one team wanted to use one and we had to end up taking it from them.

Re: Question about carts
 

I have decided to remove the battery from the design for the reason of having plugs around 90% of the time.

Let me thank you for clearing this up, because i have heard about some teams having them on carts, but it is good to receive clarification from someone that has been an inspector!

Re: Question about carts
 

It's an old butchers block. The support is exactly what you see in the pictures - 1" plywood. No other support needed!

Re: Question about carts
 

I'm not sure if this will help you, but I remember seeing a rather avant garde cart at the NYC regional last year. It was essentially a low-ish store bought tool chest with wood blocks fixed onto it to prop the robot up and handlebars. Now, as to the 4 castors vs. 2 fixed 2 steering arguement, we've recently been using 4 castors. We do have an older robot cart that has 2 fixed and 2 steering wheels, but even getting it out of our storage area is a huge hassle, so if you can, try for 4 castors. The cart moving on us has never really been a problem, as there's usually something lying around we can use as brakes. That said, our old robot cart is also on the chunkier side, while our current robot cart is more minimalist.

Re: Question about carts
 

I believe the OP is looking for a tool chest/ work bench cart. Not a robot cart, Given that I'd recommend checking out MOE's (365) pit set up. I believe they have their CAD models and material lists posted on their website.

340 Build a battery/ bumper cart, that works really well. Its basically just a two wheeled dolly, with some added compartments for batteries and bumpers. One of the huge benefits of a system like this is when your testing or practicing in a gym you can easily wheel down the whole cart of batteries and plug them in. If all your chargers are contained in the work benched you have to wheel down and set the whole system up to be much use.

I can't find a great picture of the battery cart. But i've attached what i have if you want more information I can get you in touch with someone. https://www.facebook.com/photo.php?f...type=3&theater

Re: Question about carts
 

Got a source? Neither the FRC Administrative Manual nor the FIRST Safety Manual says anything about deep-cycle batteries that I can find. On the robot, sure--everyone has to use the same batteries, and that's in the rules. Not on the robot, I see nothing at all to prevent someone from bringing one in, barring safety concerns (and if the battery is handled properly, not a concern).

Re: Question about carts
 

I'd also like a source on this. We have a lawn tractor battery and a UPS in our cart that charges in the pits with a standard computer power cable. We use the battery to provide power for our UPS and the UPS to charge our driver station as well as an electric linear actuator that lifts our robot from 18" off the ground to 36" or anywhere in between. This makes our robot cart a huge resource for us in the pits for working on the robot at a comfortable height, but has also proved to be an amazing resource during eliminations for keeping our DS charged and ready. We have even loaned our cart to other teams to work on their robots during eliminations.

Re: Question about carts
 

Best way to be absolutely sure about the legality of something with FIRST FRC is to ask in the official FIRST forum. I would ask early as this is a pretty straight forward question.

Generally, from what I have seen, people manage to get batteries that are not FRC legal into carts and pits as long as someone does not catch it. That is not exactly the most reliable tactic in the end and I prefer not to encourage people to find ways to stash things that really could be dangerous if done improperly or with people unaware.

Re: Question about carts
 

You are implying that having a non-FRC-legal battery anywhere in the venue is illegal*. This is simply not stated anywhere in the rules. Because it is not stated as illegal, it should be considered to be legal** until an official source--including Q&A--says otherwise. Which is why two people have asked for a source for the illegality ruling at one event.

The above does NOT apply to batteries used to power the ROBOT, because that is specifically covered by the Robot Rules as illegal.


*Besides the obvious laptop/cell phone/camera/other integrated batteries that aren't in a prohibited device, of course.
**Unsafe should be considered to be illegal, per the rules. Also note that this approach follows the same approach as the rest of the rules--if an item/action is not prohibited, it is permitted.

Re: Question about carts
 

Define 'unsafe'?

The robot carts do not have an Earth ground...is that unsafe? Some would say yes if there's an inverter.

A top terminal battery could easily have something fall on the terminals...does that make it unsafe all the time? Some might say yes.

If the battery is not maintenance free is it more or less safe? Some could argue this point.

So the risk you take here is that your idea of 'safe' is not someone else's idea of 'safe'.

As far as something that is not explicitly denied being permitted within a FIRST venue:
A safety inspector can undo that in a blink of an eye.
I've seen it often enough not to take it for granted.

In point of fact if we entrust the safety people with the call on that you might get a different result from venue to venue.
I doubt you'd like to have a cart that is legal until say Championship then you have to take it apart.

The best way to 'settle' this is to get an official statement from FIRST.
Not from me or another volunteer.
Then you can point to the simple to ask question and say: I respectfully disagree.

After all this is FIRST's brand at stake here.
Also please recognize that FIRST trains several volunteer roles.
It would be to FIRST's benefit to provide training that suits the actual job requirement.
If FIRST is going to allow other large batteries in use at the venues they should know to update their training.
FIRST might even need to include a hazmat clean up kit in their spare parts kit.

Also there may be legality issues in some jurisdictions about certain kinds of batteries in certain quantity within a highly populated structure like a venue. Though, off hand, I can't think of any in New Jersey.

Re: Question about carts
 

Might I also point out that this statement also applies to the robot itself?

I agree with this, just for the record.

Re: Question about carts
 

This is quite true. However the robots are generally voltage limited because of the bypass diodes on the motors (this would be the only legal source I can think of that would generate a large voltage non-static pulse).

A large battery on a cart would encourage things like 110VAC inverters.

Even though I have a battery to charge a laptop I use an automotive laptop charger it's a DC/DC converter and relatively sealed.

If we start with lots of 110VAC inverters next there will be outlet strips and outlet strips plugged into outlet strips (bad idea).

This is not really up to me and I don't want it to be.
FIRST should do their due diligence and make the call.

There are what? 3 topics on this. Clearly it's important enough someone should just ask officially.
The sooner the better really. While there's lots of time to alter course.

Re: Question about carts
 

I am in no way trying to give an official response but I'm going to give my input from experience. We carried the deep cycle to the driver stations to keep are crummy laptop charged. It was also used charge batteries on the cart with a DC/DC charger.

At are first regional (GTRE) we asked the safety inspector about the deep cycle. He said its fine but he would like us to cover the terminals to prevent shorts. Another safety inspector requested that we put the battery in a box for our next regional because it looked unsightly on the field.

In response to this we built a nice looking case out of wood for Waterloo. At the comp we asked the safety inspector about the deep cycle and he awarded us safety tokens for the case. A second inspector later awarded us more safety tokens for the case.

Re: Question about carts
 

During my time with 1075, we had a custom motorized forklift-cart, which had 2 large deep-cycle marine batteries powering it, (and a compressor, and the programming laptop, and, and, and)

It made appearances at GTR and Waterloo, and while the safety advisors DID have lots to say about it, we'd pre-emptively quelled most of their concerns by having numerous lockouts. The cart would not move, unless the driver was seated in the driver's seat AND was pushing TWO lockout buttons on the joystick, AND the front bumper of the cart was not touching something. Additionally, it had a horn and rotating light (ca. 2003) for alerting people of its presence, and a team of people who would keep the path clear for it when moving. The batteries it carried were never considered to be a concern (though they were reasonably contained by its body).

Re: Question about carts
 

I remember something like this at GTR in 2005 although I thought it was 1305 who had the forklift driving cart. It was really cool!

Re: Question about carts
 

1075's was built for the 2008 season.

I can't remember who all has had a powered cart at GTR. There have been several teams, and I know 2013 is among them.

Re: Question about carts
 

I think this is a problem. They are supposed to be Safety Advisors. Not inspectors. Unless they can point to a rule (either in the FRC manual, the venue guidelines, or something like the NEC), I do not believe their opinions should be considered any more binding than those of any other volunteer.

I have seen a Safety Advisor tell a student he must wear gloves when using a power drill. I have had Safety Advisors tell me they wanted to encourage the practice of continuously shouting "Robot!" when moving a robot anywhere outside a pit. I do not take them for granted, but neither do I take them as law.

Re: Question about carts
 

I agree. However I often find that sorting out something like all these battery powered carts is best done by FIRST. I really don't want to sit there with someone trying to make or break the case of whatever the situation is. I think the more people get asked the bigger the official/unofficial knot.

FIRST can easily settle this by addressing what they will and will not tolerate on those carts as far as batteries. If the non-FRC style batteries are allowed then the specifics can be worked out, specified or left to the people at the event. I am 'up in the air' over it as far as safety is concerned. I see the risk and also I see the ways it could be done safe enough.

If FIRST gives an answer it just leaves more time to deal with so many other issues.

Stuff like this turns into the 'bag and tag' debacle.
Bags with no tags or tags with no bags.
People worried they will get 'busted' at the next event.
Was such a headache at Mount Olive we had to call in for official response.
No issue with the idea...just no resources to comply with it.

Re: Question about carts
 

Our cart is on a motorized wheelchair base, and that has a pretty big battery, and we have never gotten any trouble for it, so I would say the battery isn't really an issue.

Re: Question about carts
 

Are you using a non-sealed lead-acid battery or a sealed type like that on the robot? The initial suggested battery (by the way, the OP is no longer considering this option) was a deep cycle spillable lead-acid battery. Lead-acid batteries product hydrogen while charging and are a potential safety hazard given certain conditions.

I don't see a problem with using a motorized cart, so long as appropriate design considerations are made: speed is no faster than a moderate walking pace, a dead man switch or emergency stop is in place, a beeper/flasher or other acoustic or visual device to inform those around that it is powered, and the batteries of the sealed, non-spillable type. In my opinion, however, it adds needless complexity and weight to what I believe is a very simple device.

Re: Question about carts
 

Given the culture of safety that is built into FIRST competitions, I'd like to hope we have the respect for other teams to think that they would take into consideration items like this. The general idea between using a large deep cycle battery is to gain the benefit of a large reserve capacity so charging at an event should be a non-issue. With that said, even if you are charging a battery at an event, charging in an open area like a gymnasium or similar area should be another non-issue as long as there is some ventilation.

There are some things that I can agree the rules should address. I don't think that this is one of them. There are enough people at a competition to observe and make recommendations about safety aspects. I don't want to see the rule book increasing in size again after it was shrunk down. It's hard enough to get kids to read the whole thing the amount of times that I ask them to.

If we ask for rules on every last item that could ever prevent the slightest possibility of an unsafe condition, we run the risk of crushing opportunities for innovation. Im not saying I'm not in support of a perfectly safe environment, just that if the people who make the final call are in New Hampshire, it would be hard to judge a system they have never seen or witnessed operating. We have had a number of things that have been quoted to us as safety law that I would never let a student do for fear of personal injury. I don't even want to start thinking about the event electrical wiring set-ups at some of the events I've been to in the past three years...

Re: Question about carts
 

It is NOT a FIRST rule, it is a event and safety advisor rule. Some events are held on a floor that have a sensitive floor to acid type chemicals(ex. Basketball arenas). FIRST knows this and has ways of covering the damages from a robot, but not a battery to charge your cart.

Re: Question about carts
 

There is no such thing as a "safety advisor rule". The green-shirted volunteers are there to give advice and promote best practices. They do not have the authority to make rules.

I'll go along with venue restrictions beyond what's in the FRC manual, as long as they actually come from representatives of the venue.

Re: Question about carts
 

If FIRST is okay with venue restrictions that vary they ought to clarify that sort of thing.

It makes it hard to build unique things when you wonder if you'll make it half way through the season before finding yourself having to take it all apart.

At least if we know that some venues allow nonFIRST style batteries on the carts and others do not; people will know to ask the question about the venue at that level.

Let us not forget there are plenty of rookies. It is not really fair to them that they have to guess about things like that either. They may not know the venues or even who to ask.

There are really 3 answers to this: yes, no, maybe

As far as the size of the manual. I worry more about the quality than the quantity.

Re: Question about carts
 

They do. I've seen it in the past few years of the Administrative Manual, at the end of section 4. Here's an excerpt:

"Please read the following common site restrictions and adhere to them in order to promote an orderly, safe, pleasant and exciting competition. Please refer to Section 4.2 of this manual section for additional site restrictions at your event."

Re: Question about carts
 

This is true and section 4.2.2 defines a bunch of loose parameters for the carts at the events. With only this mention of electrical safety:

"Do not add music or other sound devices to the cart; and"

That is definitely a rule that has been ignored in the past.
Though no mention of other electrical apparatus on carts.